This diagram is often referred to the “Iron Triangle” or “Triple Constraint” when it comes to Project Management. I first saw a similar venn diagram illustration in relation to graphic design, designed by Colin Harman), and the relevance was soon picked up by the architecture community.
The three opposing points if the triangle are:
– QUALITY: good > shoddy (size/scope/features/detailing/sustainability)
– COST: cheap > expensive (your budget for the whole project, including construction cost)
– TIME: fast > slow (the program for the delivery of architectural services, as well as the construction program)
I created my own version, as a discussion piece for use with my clients – as it is helpful for setting your priorities for the project, and understanding that being able to achieve all three simultaneously is an unrealistic goal…although we can all dream!
The idea is that you can only “pick two”. Or you might find that there is one corner of the triangle that is a much higher priority for you. The closer you move towards one point, the more this will impact the other two sides of the triangle.
– If you want your home built cheap and fast, then it will not be of good quality.
– If you want a high quality home on a small budget, then it will take time.
– If you want your home built quickly, yet also of a premium quality, then it will be a much higher cost.
So where do you think the following buildings might fit on the spectrum?
A project home?
An owner-builder with hand-crafted features?
A multi-residential development?
An investment property to be flipped quickly?
A restoration to a heritage building?
A custom architect-designed home?
However It is not as simple as just these three parts – in terms of the size/scope AND different levels of quality/crafstmanship/detailing and energy-efficiency considerations, etc. This creates a more complex layering at the ‘quality’ end of the triangle.
i.e. if the project is very large but of average quality (think McMansions), then it could be the same cost/time as a smaller sustainable and energy-efficient home of the highest quality.
An architect colleague has done a more thorough analysis of the iron triangle with these 4 dimensions (iron-tetrahedron perhaps?!)
What about sustainability?
A truly sustainable home is usually smaller (not a McMansion!) which can bring the cost down as every square metre equates to more dollars. A green home usually means that the quality of the design and build is higher than standard (i.e. double or triple-glazing, more insulation, more care taken to seal gaps, etc.) and therefore the up-front cost will also be higher…however the running costs will end up being much lower over the life of the building, and will actually save you money!
We hope this has been some food for thought for you when considering your project.
What is the priority for your home? Quality, Cost or Time – of the impossible utopia?! I’d love to hear about it in the comments below!
We aim to answer questions about sustainable design, green buildings and healthy homes, also with reference to our local climate (Regional Ballarat area and Melbourne) in future articles. Don’t forget you can sign up to receive our news so you won’t miss out on our posts!